In general, the size, weight, and the like of a wireless terminal are major constraints in developing a wireless terminal with enhanced mobility. These constraints are obstacles to increasing the battery capacity of the wireless terminal.
Accordingly, there exists a need for reducing power consumption of the wireless terminal in consideration of the limited battery capacity. For example, idle mode and connected mode are basic modes for the wireless terminal. If a predetermined condition is satisfied in a basic mode, the wireless terminal operates in standby mode. A major example of the standby mode is Discontinuous Reception (DRX) mode. For the convenience of description, the term DRX mode will be used uniformly.
The DRX mode supports a sleep state and an active state. The wireless terminal performs only a minimum required operation in the sleep state to reduce power consumption, whereas the wireless terminal performs a normal operation in the active state. The minimum required operation may be to monitor a paging signal in specific slots preset between the wireless terminal and a base station.
In the DRX mode, the wireless terminal wakes up only in predetermined slots and sleeps in the other slots. Therefore, the wireless terminal can reduce power consumption in the DRX mode.
Since the wireless terminal wakes up only during a specific interval (an allocated slot) and monitors a paging message from the base station and sleeps during the remaining interval, the power consumption of the wireless terminal can be reduced. Most of the components of the wireless terminal are inactive in the sleep state, without power supply to these components. In this respect, the sleep state is also called a power saving mode.
As described above, the wireless terminal repeats a wake-up state (i.e. an active state) and a sleep state in the DRX mode. Upon detection of a paging message directed to the wireless terminal from the base station in the wake-up state, the wireless terminal performs a necessary process.
Control programs that control a connected mode operation and a DRX mode operation of the wireless terminal are stored in a main memory. Therefore, the wireless terminal accesses the main memory, reads a related control program, and loads the read control program in a cache memory to thereby perform an operation according to a current situation. The same thing applies to the DRX mode.
For example, a processor of the wireless terminal accesses the main memory, reads a control program required to receive a paging message, loads the read control program in the cache memory, and receives and processes a paging message using the loaded control program.
While the power consumption of the wireless terminal is reduced in the DRX mode, the wireless terminal should activate related hardware to access the main memory, read a related control program, and load the read control program in the cache memory, thus increasing power consumption.
Particularly, a wireless terminal having two different processors, such as a smartphone, may use power in the DRX mode. For example, the wireless terminal may be equipped with a plurality of processors serving different purposes, such as an Application Processor (AP) that provides overall control to operations of the wireless terminal and a Communication Processor (CP) that controls overall communication of the wireless terminal.
In this case, the CP is responsible for managing the DRX mode operation. Accordingly, if the AP and the CP share the main memory, some hardware block of the AP should be activated to enable the CP to read a control program from the main memory in the DRX mode. As compared to a wireless terminal having a single processor or an independent memory for each processor, this wireless terminal may consume more power.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.